Add ECMGenerateExportHeader, for improved handling of deprecated API

Summary:
Generates additional macros in the export header which can be used for
fine-grained disabling of warnings & visibility as well as excluding from
the build.

Reviewers: #frameworks, #build_system

Subscribers: chehrlic, dfaure, cgiboudeaux, kde-frameworks-devel, kde-buildsystem

Tags: #frameworks, #build_system

Differential Revision: https://phabricator.kde.org/D23789

4 files changed, 175 insertions, 0 deletions

diff --git a/tests/ECMGenerateExportHeaderTest/consumer/CMakeLists.txt b/tests/ECMGenerateExportHeaderTest/consumer/CMakeLists.txt
new file mode 100644
index 00000000..ba5940cd
--- /dev/null
+++ b/tests/ECMGenerateExportHeaderTest/consumer/CMakeLists.txt
@@ -0,0 +1,50 @@
+cmake_minimum_required(VERSION 3.0.0)
+
+project(consumer)
+
+include(CheckCXXSourceCompiles)
+include(CMakeParseArguments)
+
+include(../../test_helpers.cmake)
+
+include("${CMAKE_CURRENT_BINARY_DIR}/../installation/${LIBRARY}/lib/library/LibraryTargets.cmake")
+
+# map any "CURRENT" value to library version string
+# keep version in sync with the one used in library/CMakeLists.txt
+set(library_version 2.40.0)
+if(LIBRARY_DISABLE_DEPRECATED_BEFORE_AND_AT STREQUAL "CURRENT")
+    set(LIBRARY_DISABLE_DEPRECATED_BEFORE_AND_AT ${library_version})
+endif()
+if(DEPRECATED_EXCLUDED_BEFORE_AND_AT STREQUAL "CURRENT")
+    set(DEPRECATED_EXCLUDED_BEFORE_AND_AT ${library_version})
+endif()
+
+# load the test variant specific testAPI method
+include(testAPI_${TEST_VARIANT}.cmake)
+
+# for each API element test their visibility to the compiler and if a warning is emitted
+set(_code "Enum enumerator = Enumerator_deprecatedAt2_0;")
+testAPI(_code DEPRECATED_AT 2.0 BUILD_TIME_ONLY_DISABLABLE NO_WARNING)
+
+set(_code "Enum enumerator = Enumerator_not_deprecated;")
+testAPI(_code)
+
+set(_code "function_deprecatedAt2_0();")
+testAPI(_code DEPRECATED_AT 2.0)
+
+set(_code "function_deprecatedAt2_12();")
+testAPI(_code DEPRECATED_AT 2.12)
+
+set(_code "function_not_deprecated();")
+testAPI(_code)
+
+set(_code "Class().method_deprecatedAt2_0();")
+testAPI(_code DEPRECATED_AT 2.0 BUILD_TIME_ONLY_DISABLABLE)
+
+set(_code "Class().method_deprecatedAt2_12();")
+testAPI(_code DEPRECATED_AT 2.12 BUILD_TIME_ONLY_DISABLABLE)
+
+set(_code "Class().method_not_deprecated();")
+testAPI(_code)
+
+add_executable(dummy main.cpp)
diff --git a/tests/ECMGenerateExportHeaderTest/consumer/main.cpp b/tests/ECMGenerateExportHeaderTest/consumer/main.cpp
new file mode 100644
index 00000000..0f45ea60
--- /dev/null
+++ b/tests/ECMGenerateExportHeaderTest/consumer/main.cpp
@@ -0,0 +1,4 @@
+int main(int, char**)
+{
+    return 0;
+}
diff --git a/tests/ECMGenerateExportHeaderTest/consumer/testAPI_DISABLE_DEPRECATED_BEFORE_AND_AT.cmake b/tests/ECMGenerateExportHeaderTest/consumer/testAPI_DISABLE_DEPRECATED_BEFORE_AND_AT.cmake
new file mode 100644
index 00000000..fac51d53
--- /dev/null
+++ b/tests/ECMGenerateExportHeaderTest/consumer/testAPI_DISABLE_DEPRECATED_BEFORE_AND_AT.cmake
@@ -0,0 +1,71 @@
+function(generate_hex_number _var_name _version)
+    set(_hexnumber 0)
+
+    set(version_regex "^([0-9]+)\\.([0-9]+)\\.([0-9]+)$")
+    string(REGEX REPLACE ${version_regex} "\\1" _version_major "${_version}")
+    string(REGEX REPLACE ${version_regex} "\\2" _version_minor "${_version}")
+    string(REGEX REPLACE ${version_regex} "\\3" _version_patch "${_version}")
+    set(_outputformat)
+    if (NOT CMAKE_VERSION VERSION_LESS 3.13)
+        set(_outputformat OUTPUT_FORMAT HEXADECIMAL)
+    endif()
+    math(EXPR _hexnumber "${_version_major}*65536 + ${_version_minor}*256 + ${_version_patch}" ${_outputformat})
+    set(${_var_name} ${_hexnumber} PARENT_SCOPE)
+endfunction()
+
+
+generate_hex_number(disable_deprecated_before_and_at_hexnumber ${LIBRARY_DISABLE_DEPRECATED_BEFORE_AND_AT})
+
+if(GROUP_MODE STREQUAL "GROUP_USE_GROUP")
+    set(_deprecation_macros_base_name "LIBGROUP")
+else()
+    set(_deprecation_macros_base_name "LIBRARY")
+endif()
+
+function(testAPI code_var_name)
+    set(options BUILD_TIME_ONLY_DISABLABLE NO_WARNING)
+    set(oneValueArgs DEPRECATED_AT)
+    set(multiValueArgs)
+    cmake_parse_arguments(ARGS "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+
+    if((NOT ARGS_DEPRECATED_AT) OR
+       (ARGS_BUILD_TIME_ONLY_DISABLABLE AND ARGS_DEPRECATED_AT VERSION_GREATER DEPRECATED_EXCLUDED_BEFORE_AND_AT) OR
+       (ARGS_DEPRECATED_AT VERSION_GREATER LIBRARY_DISABLE_DEPRECATED_BEFORE_AND_AT))
+       set(_build_result_expected TRUE)
+    else()
+       set(_build_result_expected FALSE)
+    endif()
+
+    set(CMAKE_REQUIRED_LIBRARIES library)
+    set(CMAKE_REQUIRED_DEFINITIONS "-D${_deprecation_macros_base_name}_DISABLE_DEPRECATED_BEFORE_AND_AT=${disable_deprecated_before_and_at_hexnumber}")
+
+    set(_code "
+#include <library.hpp>
+int main(int, char**)
+{
+    ${${code_var_name}}
+}
+")
+
+    unset(_result CACHE) # clear out as check_cxx_source_compiles caches the result
+    check_cxx_source_compiles("${_code}" _result)
+
+    assert_var_bool_value(_result ${_build_result_expected})
+
+    # check warning 
+    if(_build_result_expected)
+        if((ARGS_BUILD_TIME_ONLY_DISABLABLE AND NOT ARGS_NO_WARNING) OR
+           (NOT ARGS_BUILD_TIME_ONLY_DISABLABLE AND ARGS_DEPRECATED_AT AND
+            ARGS_DEPRECATED_AT VERSION_GREATER LIBRARY_DISABLE_DEPRECATED_BEFORE_AND_AT))
+            set(_dep_warning_result_expected FALSE)
+        else()
+            set(_dep_warning_result_expected TRUE)
+        endif()
+
+        set(CMAKE_REQUIRED_FLAGS "-Werror=deprecated-declarations")
+        set(CMAKE_REQUIRED_DEFINITIONS) # unset LIBRARY_DISABLE_DEPRECATED_BEFORE_AND_AT, as LIBRARY_DEPRECATED_WARNINGS_SINCE defaults to it
+        unset(_dep_warning_result CACHE) # clear out as check_cxx_source_compiles caches the result
+        check_cxx_source_compiles("${_code}" _dep_warning_result)
+        assert_var_bool_value(_dep_warning_result ${_dep_warning_result_expected})
+    endif()
+endfunction()
diff --git a/tests/ECMGenerateExportHeaderTest/consumer/testAPI_NO_DEPRECATED.cmake b/tests/ECMGenerateExportHeaderTest/consumer/testAPI_NO_DEPRECATED.cmake
new file mode 100644
index 00000000..190ccecc
--- /dev/null
+++ b/tests/ECMGenerateExportHeaderTest/consumer/testAPI_NO_DEPRECATED.cmake
@@ -0,0 +1,50 @@
+if(GROUP_MODE STREQUAL "GROUP_USE_GROUP")
+    set(_deprecation_macros_base_name "LIBGROUP")
+else()
+    set(_deprecation_macros_base_name "LIBRARY")
+endif()
+
+function(testAPI code_var_name)
+    set(options BUILD_TIME_ONLY_DISABLABLE NO_WARNING)
+    set(oneValueArgs DEPRECATED_AT)
+    set(multiValueArgs)
+    cmake_parse_arguments(ARGS "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+
+    if((NOT ARGS_DEPRECATED_AT) OR
+       (ARGS_BUILD_TIME_ONLY_DISABLABLE AND ARGS_DEPRECATED_AT VERSION_GREATER DEPRECATED_EXCLUDED_BEFORE_AND_AT))
+       set(_build_result_expected TRUE)
+    else()
+       set(_build_result_expected FALSE)
+    endif()
+
+    set(CMAKE_REQUIRED_LIBRARIES library)
+    set(CMAKE_REQUIRED_DEFINITIONS "-D${_deprecation_macros_base_name}_NO_DEPRECATED")
+
+    set(_code "
+#include <library.hpp>
+int main(int, char**)
+{
+    ${${code_var_name}}
+}
+")
+
+    unset(_result CACHE) # clear out as check_cxx_source_compiles caches the result
+    check_cxx_source_compiles("${_code}" _result)
+
+    assert_var_bool_value(_result ${_build_result_expected})
+
+    # check warning
+    if(_build_result_expected)
+        if(ARGS_BUILD_TIME_ONLY_DISABLABLE AND NOT ARGS_NO_WARNING)
+            set(_dep_warning_result_expected FALSE)
+        else()
+            set(_dep_warning_result_expected TRUE)
+        endif()
+
+        set(CMAKE_REQUIRED_FLAGS "-Werror=deprecated-declarations")
+        set(CMAKE_REQUIRED_DEFINITIONS) # unset LIBRARY_DISABLE_DEPRECATED_BEFORE_AND_AT, as LIBRARY_DEPRECATED_WARNINGS_SINCE defaults to it
+        unset(_dep_warning_result CACHE) # clear out as check_cxx_source_compiles caches the result
+        check_cxx_source_compiles("${_code}" _dep_warning_result)
+        assert_var_bool_value(_dep_warning_result ${_dep_warning_result_expected})
+    endif()
+endfunction()